NASHVILLE, Tenn. — On the radio, it has displaced Top 40 as the most popular musical format.

Its biggest star — Taylor Swift, a 24-year-old phenomenon — earns more from music than any other singer: almost $40 million last year, according to Billboard magazine.

And, in June, Rolling Stone, the rock ’n’ roll bible, will introduce a website devoted to the genre.

Country has long been a mainstay of American music. Yet, as the music industry continues to struggle financially and once-dominant types of music such as hip-hop recede on the charts, the country audience has grown stronger, wider and younger — a fact that hasn’t escaped the notice of media companies that have invested heavily in the genre.

“Nashville has become a musical superpower,” said Scott Borchetta, CEO of Big Machine Label Group, the record company behind Swift and other popular acts such as the Band Perry and Florida Georgia Line.

Nashville, country music’s spiritual and commercial home, has in recent years acquired some glamour with help from Nashville, the ABC prime-time soap opera about country divas. Much as Dallas did for that city in the 1980s, the show, filmed in Nashville and featuring Connie Britton and Hayden Panettiere, has given the city a sexier spot on America’s pop-culture map.

That map has always included a country star or two, whether it was Garth Brooks and Shania Twain in the 1990s or Kenny Rogers and Dolly Parton in the ’70s and ’80s.

But country’s latest wave — led by telegenic and Web-savvy young stars such as Swift, Luke Bryan and Blake Shelton — has been accompanied by changes in media consumption. Traditional album sales are falling while streaming audio, social media and online video take hold among fans.

“Nashville has just embraced younger artists and let them pass through the gates quicker and with less resistance than in the past,” said Allen Shapiro, CEO of Dick Clark Productions, which presented the Academy of Country Music Association awards show on April 6.

A rival show, the Country Music Association Awards, takes place each November in Nashville.

One company looking to country as an avenue into a multiplatform future is Cumulus Media, a national chain of about 460 radio stations. Last year, it introduced a country-themed brand, “Nash,” when it opened WNSH, or Nash FM, in New York, the city’s first country station in 17 years.

Cumulus wants Nash to encompass not only radio but also television, print and online media, and even licensed merchandise such as kitchenware and cars.

Although country broadcasters typically give their stations names such as “the Wolf” or “the Coyote,” suggesting rural stereotypes, Lew Dickey, CEO of Cumulus, said his new brand captures an upwardly mobile audience.

“We wanted to eschew the conventional stereotypes in the format and go with something more aspirational,” Dickey said. “Nash is cool; Nash is fun; Nash is relevant.”

Country’s popularity on the radio is reflected on the road.

Live Nation recently reported that audiences for its country concerts grew 50 percent last year to 7 million, and the company said that it now views country as one of its two fastest-growing genres, along with electronic dance music.

Other forms of media have also taken notice. Rolling Stone recently opened an office on Music Row and is preparing to introduce the website Rolling Stone Country.

Kix Brooks, who sold 27 million albums as part of the country duo Brooks & Dunn, hosts two shows for Nash.

“I don’t think country music is hick music anymore,” he said. “It’s not hay bales and cornfields.”